8:36am Thursday 14th May 2009
By Keith Thomson
The recent Budget included various initiatives to reduce CO2 emissions, though they fell short of the proposals in many other countries.
Perhaps the most impressive is the support for electric cars, with at least 50,000 people receiving up to £5,000 each to help buy such vehicles in 2011, and it is a sensible kick-start to a timely change in motoring. Though ideally we need people to walk more, use cycles, and travel by bus and train, this is unlikely to seriously reduce the 15 per cent of the UK’s emissions caused by private cars that are too convenient as well as being status symbols.
So we need to find a way of driving without producing so much CO2, and this will be necessary anyway with oil becoming scarce and more expensive.
The real advantage of an electric car is that it’s much more energy-efficient than a petrol or diesel engine. A battery will deliver more than 80 per cent of its electrical energy into motion, whereas less than 25 per cent of the chemical energy in petrol can be used to turn the wheels.
It means that electric cars will be cheaper to run than fossil fuel ones. A petrol car driven for 40 miles in one hour will use at least a gallon of fuel – about £5 – whereas the average electric car needs only seven kilowatts at a cost of 80p.
With no gear box, complicated transmission or cooling system, an electric car will be lighter and cheaper to maintain, repair and insure. Two pedals aren’t a problem and the acceleration can be startling, better than most petrol cars. Usefully, electric cars are quiet, with no tailpipe pollution and city air would be cleaner with definite health benefits.
Real progress will depend on the new generation of lithium-ion batteries that can store enough power for 120 miles and speeds of up to 60 mph. They can be recharged at night, when electricity is cheaper, or at the workplace, and if the electricity is from a renewable source, then the cars will be CO2-free.
However, even if the electricity was from a coal-fired station, a seven KW car would only produce three kilos of CO2 an hour compared to ten from a petrol car.
Exceptionally, cars on charge at night could have the battery power reversed back into the grid to meet peak demand and so reduce the need for additional power stations.
Electric cars will be commonplace by 2020, despite the efforts of Top Gear.
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